Resistance is a measure of the degree to which an object opposes the movement of electric charge.
The resistance of a resistor with uniform geometry is proportional to its resistivity and length and is inversely proportional to its cross-sectional area
Resistivity is a fundamental property of a material that depends on its atomic and molecular structure and quantifies how strongly the material opposes the motion of electric charge.
The resistivity of a conductor typically increases with temperature.
Ohm’s law relates current, resistance, and potential difference across a conductive element in a circuit.
Materials that obey Ohm’s law have constant resistance for all currents and are called ohmic materials.
The resistivity of an ohmic material is treated as constant regardless of temperature.
Resistors can also convert electrical energy to thermal energy, which may change the temperature of the resistor and the resistor’s environment.